Device at expandable mounting sleeve

ABSTRACT

The invention concerns expandable fastenings of the kind that includes a conical shaft part (2) and a conical expandable sleeve (4) that is pressed up on the conical part (2) of the shaft (1) in order to fill out and fasten the shaft in a mounting hole. The expandable sleeve (4) is pressed against the cone by a washer (5) and by a nut (11) screwed onto a threaded end portion of the shaft. The washer (5) is on its outside provided with a thread for the threading thereon of a nut part or sealing ring (6). The expandable sleeve (4) and the threaded washer (5) are connected by hooklike flanges so that the sealing ring (6) can also be used to pull out the sleeve from the conical axle part.

BACKGROUND OF THE INVENTION

This invention related to expandable fastening means in particular stubaxles and shafts. By using expandable means a very rigid fastening isobtained that is unlikely to losen. Sooner or later however thefastening means must be losened in order to exchange the bearingscarried by the shaft. This is however not fully as simple as it sounds.To start with there is always the risk, with the embodiments existingtoday, that dirt enters into the fastening as well as water, andcorrosion and pollution result in that the expandable element will stickso hard that it will become close to impossible to loosen and remove theshaft. The result is often that excessive force is used, which in turncan make the reassembly of the mounting impossible, difficult orexpensive, due to damages on the shaft itself or the fastening brackets.

SUMMARY OF THE INVENTION

In view of the above problems an object of the invention is to provideimproved sealing for shafts fastened with expandable elements and thelike. Another object of the invention is to faciliate nondestructivedisassembly.

BRIEF DESCRIPTION OF THE DRAWING

The FIGURE is a longitudinal sectional view of the device according tothe invention. Further advantages and features of the invention arereadily apparent from the following description of a preferredembodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

On the drawing one end of a shaft 1 is shown. The shaft is mounted intwo brackets of which only one is shown. On the shaft a bearing isarranged. The resulting joint can be used to connect pivotable arms,pistons, piston rods etc.

The shaft 1 has in its outer end a conically tapering part 2 and outsideof this a threaded part 3. Between the shaft 1 and the essentiallycylindrical hole in the bracket is arranged a sleeve 4 with wedge-likelongitudinal section. The tapering of the conical part 2 of the shaft 1and the sleeve 4 coincide, and the sleeve 4 is provided with slotsextending from alternating ends of it so that the sleeve is easilyexpandable. In this way the sleeve 4 can be expanded by a forcing thesleeve 4 onto the conical part 2 of the shaft so that the hole 12 isfilled up and a secure fixing is obtained for the shaft 1. In order topush the sleeve 4 against the conical part 2 of the shaft a washer 5 isarranged to be pushed over the outer threaded part 3 of the shaft andwith an outer diameter less the hole 12 for the fastening of a joint.The washer 5 is pressed against the sleeve 4 by a nut 11 threaded on thethreaded part 3.

The washer 5 has at its outer circumference a thread 10 on which aftermounting a sealing and demounting ring 6 is threaded. The side towardsthe bracket is provided with an O-ring or seal 7. In this way it iscertain that no dirt whatsoever can enter into the expanding parts. As aresult hereof no pollution or corrosion takes place and the parts becomeeasier to demount. Within the concept of the invention it is of coursealso possible to consider a sealing ring 6 constituted by a domed nutalso protecting the nut and threaded part of the shaft.

In order further to facilitate demounting or disassembly of theexpandable device the sleeve 4 and the washer 5 are connected grippinginto each other with hooklike circumferencial protrusions or blunges.For the sleeve 4 these protrusions are turned inwards and for the washer5 turned outwards. Preferably the cooperating gripping surfaces areslightly iclined with the apex of the corresponding cone turned towardsthe axle 1. In this way at demounting the nut 11 is first removed andthen the sealing ring 6 is unscrewed and again treaded on the washer 5with the seal 7 turned outwards. The turning of the ring 6 then pullsthe washer 5 outwards together with the expandable element 4. The ring 6is preferably provided with an outer key grip.

Within the frame of the invention it is also possible to consider thenut 11 and washer 5 integrated with each other, for which case thewasher 5 is preferably turnable relative the sleeve 4. In case that thewasher 5 does not have any key grip however it is preferably fixed in aturnable direction relative to the sleeve 4 so that the fastened sleeve4 holds the washer 5 against rotation when the ring 6 is turned in orderto pull the sleeve 4 outwards.

Instead of the above hooking of sleeve 4 and washer 5 it is of coursealso possible to consider bajonet grip.

The expandable fastening is in particular intended for the use in heavymachinery to connect piston rods and pistons pivotably with two opposedidentical fastenings of the type described. By means of the inventionthe holes in the mounting brackets can be big enough to allow the shaft1 to be entered through the holes. Furthermore each end of the shaft ismounted independently and the two fastening brackets will not besubjected to any contracting pressure against each other. Since nopretension prevails the resistance against tension for the total devicewill be better than otherwise.

Between the two brackets the bearing of the pivotable parts will bearranged and the so to say inner side of the fastenings will besubjected to a constant presence of lubricants under pressure. In orderto prevent this lubricant from seeping away from the fastening means tothe outside sealing ring 6 and seal 7 cooperate to keep the lubricantwhere it should be, including the protection of the sleeve 4 and thesurfaces of hole and shaft.

When sealing the fastening it is of course not permitted to subject ring6 to so great turning toques that the washer 5 is deformed and thesleeve 4 is subjected to removable pressures.

It is of course also possible to arrange a threaded hole in the shaft 2and use a bolt instead of a threaded part 3 and nut 11.

I claim:
 1. An expandable device for attaching a shaft to a hubcomprising:a shaft having a truncated conical end; an expandable sleevehaving an inner conical surface mating with the truncated conical endand an exterior surface mating with a mounting hole in the hub; athreaded washer having a threaded outer surface and adapted to rotatablyinterconnect with one end of said expandable sleeve; a threaded partextending axially from said truncated conical end of said shaft andthrough said treaded washer; a nut mounted on said threaded part andthreaded to engage said threaded washer, said nut having an outerdiameter smaller than said outer surface of said threaded washer; and aninternally threaded ring adapted to be threaded onto said outer surfaceof said threaded washer and engageing said hub.
 2. Device according toclaim 1, characterized in that the expandable sleeve and the threadedwasher are connected by cooperating gripping surfaces allowing relativemovement axially so that the expansion of the sleeve is not hindered. 3.Device according to claim 2, characterized in that the threaded washerand the expandable sleeve are freely rotatable relative to each other.4. Device according to claim 2, characterized in that the threadedwasher and the expandable sleeve are locked relative to each otheragainst the rotation.
 5. Device according to claim 2, characterized inthat an outer diameter of the threaded washer is less than an innerdiameter of the mounting hole.
 6. Device according to claim 1,characterized in that the threaded washer and the expandable sleeve arefreely rotatable relative to each other.
 7. Device according to claim 6,characterized in that an outer diameter of the threaded washer is lessthan an inner diameter of the mounting hole.
 8. Device according toclaim 1 characterized in that the threaded washer and the expandablesleeve are locked relative to each other against rotation.
 9. Deviceaccording to claim 8, characterized in that an outer diameter of thethreaded washer is less than an inner diameter of the mounting hole. 10.An expanding device as in claim 9 wherein:the threaded outer peripheryof said washer has a diameter less than that of the hole in the hub. 11.Device according to claim 1 characterized in that an outer diameter ofthe threaded washer is less than an inner diameter of the mounting hole.12. An expandable device for attaching a shaft to a hub comprising:ashaft, said shaft having a truncated conical end; an expandable sleevecircumscribing the truncated conical end and having an internal inclinedsurface mating with the truncated conical end and an exterior surfacemating with a hole in the hub; a washer having a threaded outerperiphery and adapted to rotatably interconnect with one end of saidexpandable sleeve; a threaded part attached to said shaft and extendingaxially from the truncated conical end axially through said washer; anut adapted to receive said threaded part and contact said washer, saidnut having an outer diameter smaller than said outer periphery of saidwasher; and a sealing ring adapted to be threaded onto the outerperiphery of said washer and engaging said hub, whereby said sealingring prevents dirt and contamination from entering to the shaft andadditionally facilitates disassembly of the expanding device.